diff --git a/tox.ini b/tox.ini
new file mode 100644
index 0000000..668a89d
--- /dev/null
+++ b/tox.ini
@@ -0,0 +1,11 @@
+[tox]
+envlist = py27, pypy, py34, py35, pypy3
+
+[testenv]
+commands = {envpython} test_contextlib2.py
+
+[testenv:py27]
+deps = unittest2
+
+[testenv:pypy]
+deps = unittest2